Madariaga is a Basque surname. It is derived from word madari (Basque for pear) Notable people with the surname include:
Francisco Javier Solana de Madariaga, KOGF (born 1942), Spanish physicist and Socialist politician
Joaquín Madariaga (1799–1848), soldier and Argentine politician
José Cortés de Madariaga (born 1766), South American patriot
Juan Madariaga (1809–1879), Argentine general who participated in the civil wars of the nineteenth century
Julen Madariaga (born 1932), Basque Spanish politician and lawyer who co-founded the Basque armed separatist group ETA in 1959
Modesto Madariaga (1904–1974), Spanish aviation mechanic
Nieves de Madariaga or Nieves Mathews (1917–2003), author of Scottish and Spanish parentage
Salvador de Madariaga (1886–1978), Spanish diplomat, writer, historian and pacifist